This invention relates generally to a musical instrument, and in particular to an adjustable saddle for use with a stringed musical instrument such as a guitar.
In a stringed musical instrument such as a guitar sound is produced by causing one or more tightly stretched strings to vibrate, the frequency at which the string vibrates, and thus the resultant sound output, being dependent on a number of factors including string length, tension and caliper (thickness). Variations in string caliper, tension and other factors, in particular--the rod-like tendency of the string near its contact points where little or no vibration is produced, make it desirable that the vibrating string length be adjustable to give true intonation wherein the instrument is tuned for producing properly pitched sounds when played. While a number of devices are known for facilitating this adjustment, none have proven altogether satisfactory, especially for acoustic guitars.
Conventionally, one end of each string of a guitar is wound upon a shaft associated with a tuning peg, the other end of the string being anchored to a bridge. The bridge typically includes a saddle having a string supporting surface fixing one end of the effective vibrating length of the strings. The other end of the effective vibrating length of each string is determined by the player when he manually engages or presses the strings against the instrument frets or, when unengaged, by the location of a string nut disposed near the guitar neck. In terms of adjusting the instrument for proper intonation, it is the string length between the saddle and the string nut which is critical and must be fixed for compensating other string variables to produce a properly pitched instrument.
Since the active length of a string may be determined at one end by either the string nut or a fret, when tuning a guitar for proper intonation, the saddle is normally used to effectuate the necessary string length adjustment. Saddles for acoustic guitars conventionally comprise elongate structures transversely disposed underlying the strings and having an upstanding string supporting surface engaging the strings. Such saddles are fixed in position in relation to the guitar sound board and thus afford essentially no intonation adjustment capabilities although sometimes slight adjustments are made by filing off small sections of the saddle. Various saddles have also been developed, particularly for use with solid body electric guitars, which comprise rather complex mechanical structures including longitudinally movable string supporting elements operated by adjustment screws or the like. These structures, however, are relatively complex and expensive and, due to their excessive mass, normally not suitable for use with acoustic guitars.